As a general rule, posts in the the Art Contribution section should be meaningful in some way--addressing a question asked by the poster, or giving C&C. Posting simply to say how "awesome something is" is a great sentiment, but when it happens every time, over every image, can get quite "noisy." Although some praising is fine, please try and make your posts more substantive than just "WOW UR KEWL." Excessive noisy comments will be split/removed.

Make a thread called Critique Guideline Discussion if you wish to discuss it: and have all posts regarding it there, to cut down on noisy threads.
NOTE: This document isn't intended to be set in stone - if you think something's missing or wrong, please say so.

It doesn't matter how good a point you have to make. If the artist isn't in a mood to hear it then you'll get nowhere and you'll alienate the artist. Remember that these guys are contributing their own time and effort because they enjoy producing art for Wesnoth. Don't make them stop enjoying it.

That said:

Section I:The technical side of critiquing

Offering a useful art critique is difficult for a number of reasons. The most obvious is a disparity in artistic skill/understanding: no two artists are at precisely the same level of skill. How can a less skilled artist ever offer useful advice to an artist with more skill? Conversely, how can an highly skilled artist offer advice in a way that a less experienced artist can understand? And if someone has no artistic experience at all, can their input ever be valuable?

Of course, artists can't be neatly ranked by skill from 'best' to 'worst'. In practice, each artist has strong and weak areas. But the principle remains: given differences in skill at different aspects of drawing, how can meaningful critique be offered?

Creation of graphics such as those used in Wesnoth involves a combination of abilities, including:

(a) conceptual/stylistic judgement and design skills;
(b) a technical understanding of how to model aspects of reality eg. knowledge of human proportion, realistic lighting and perspective; and
(c) the ability to translate the concept and understanding into an artwork. eg. skill at drawing & ability to work a paint program.

Taking these in order:

A: Conceptual/stylistic judgment and design skills

Conceptual elements of an artwork are the most subjective element of drawing, and therefore potentially the most controversial.

Fortunately, there is a common yardstick that everyone shares: how well does the artwork's concept fit into the existing setting and game of Wesnoth?

Note: This section largely assumes that we're talking about creating official Wesnoth art. Unofficial artwork - such as units for custom campaigns - should be internally consistent for maximum effect, but don't necessarily need to maintain a compatible artistic style with mainline Wesnoth.

Let's consider compliance to the common standard as a series of levels:

Level 0: Outright inconsistencies. A portrait of a Goblin Knight riding a horse is inconsistent; in Wesnoth, Goblin Knights ride wolves. Wesnoth orcs are brown; a portrait showing them as green is inconsistent. A certain degree of artistic license is required to reinterpret sprite art as a portrait, but core elements should be maintained.
Who should critique?: Anyone.

Level 1: Inconsistencies with implied setting details. Orcs are portrayed as a people who value martial skill. Though not explicitly stated, they probably value and care for their weaponry. As such, a rusty, poorly maintained sword would be a poor choice for an attack icon for an orc (a goblin, on the other hand...). Similarly, a massive blade is probably inappropriate for the (presumably comparatively weak) Elves.
Who should critique?: Anyone.

Level 2: Debatable Inconsistencies: A picture of a troll gnawing on a human leg (which would probably be rejected as too violent anyway). Is this the sort of behaviour a troll would engage in? Certainly mythical and fictional trolls sometimes behave this way, but is it appropriate for Wesnoth trolls?
Who should critique?: Anyone.

Level 3: Stylistic differences: The picture is quality and not even debatably inconsistent but it looks different because it's drawn in a different style.
Who should critique?: Core Art Developers. This is such a subtle and subjective area that only Art Developers (who choose what art is accepted in game) should say whether something is suitable stylistically or not. Note that if you're good enough, minor stylistic differences may be moot.

Level 4: Personal opinion: The artwork is of high quality, and consistent with the Wesnoth setting and style, but there's something about it you just don't like. You think the sword should be shown at a different angle, or don't think the new trolls look as good as the old ones.
Who shoul critique?: Art Developers, or anyone only if open comment was invited.

B: Technical understanding of how to model aspects of reality

Everyone with eyes has a good idea of what reality (and particularly people) look like, but only artists (and medical professionals) have detailed knowledge of the construction of the human form. The situation is similar for other aspects of reality; modelling buildings, plants, animals, etc.

Lets consider technical understanding as a series of levels:

Level 0: Blatantly wrong: A hand is on backwards.
Who should critique?: Anyone.

Level 1: Wrong: It looks okay at a quick glance, but a close look indicates a clear problem. The eyes are positioned disproportionately high in the head. The sword blade is twisted relative to the handle. The orc has unusually 'chiselled' features.
Who should critique?: Anyone.

Level 2: Probably wrong: You're pretty sure something's wrong, but you can't define what. The feet (or the hands, or the head) look 'funny'.
Who should critique: Anyone, but see below.

Level 3: Possibly wrong: Maybe its wrong, but maybe it's a stylistic thing, or maybe it's the effect of perspective. The left leg is bigger than the right, but then it is also positioned further forward.
Who should critique: Anyone, but see below.

How to critique these issues:

Contrary to apparent logic, if you don't have art training, you're probably better off providing non-detailed feedback. The higher level the issue is, the more true this is. Often, our lifetime experience of seeing allows us to intuit that something is wrong about a picture, but doesn't enable us to put our finger precisely on the problem. Trying to guess precisely what bothers us is likely to result in an incorrect conclusion. The artist will recognize that, and dismiss our concern (plus probably become irritated) even though we were correct that there was a problem.

If you can't put your finger on precisely what's wrong, be vague "Something looks wrong with the head, to me". It's not as useful as identifying the problem precisely and correctly, but is much more useful than identifying the problem precisely and incorrectly. Note:This preference varies from artist to artist, so play it by ear.

Once you've pointed the issue out, if the artist doesn't want to hear about it, let it drop.

C: The ability to 'draw'

This includes both the traditional ability to draw, and technical skill in using a paint program to tweak a work. It's the artist's ability to actually implement their concept and technical knowledge in physical (or digital) form.

Who should critique?: Someone with superior skill in the pertinent area (or subarea) only. Anyone else is incapable of providing useful advice.

Section II: The social side of critiquing
Assuming we're up to offering a technically useful critique, how do we best express it?

The cliche holds that an artist's work is like their child. But actually, it's worse than that: their work is a piece of themselves exposed for all the world to see. As such, they can be pretty sensitive about it.

Here are some hints for offering a critique in appropriate way:

1. Only critique if the artist requests it.
Some artists (eg. Neoriceisgood) post their art for inclusion in game rather than general comment. They only want to know what (if any) changes are required to have their art accepted. Similarly, if an artist has requested that critique be limited to a particular group of people, or to a particular topic, respect their wishes.

2. Suggest, don't demand.
A Wesnoth artist is a volunteer who spends their time and effort to help the community. They don't work for you, and aren't obligated to follow your directives. Artists are one of the most precious commodity Wesnoth has (along with coders); don't take them for granted.

3. Suggest, don't debate.
If you critique and the artist disagrees, drop it. You've shared your critique, it's up to them to accept it or not.

4. Offer critiques only on aspects of the work the artist is looking for.
Example: an artist uploads an outline drawing of a figure to ask if a pose looks dramatic enough. Critiquing the drawing saying that the figure needs a face is irrelevant and likely to annoy the artist who obviously knows the figure needs a face and was only looking for comments on the pose. Works that are proposed as finished pieces are open to all criticisms, assuming they follow all other guidelines.

5. Comment on the good aspects of a work as well as (and before) the critique.
Critiquing is generally picking the 1% that's wrong in a work that's 99% right. Make your critique feel that way. There's a lot that's good about the work (or presumably you wouldn't be spending your time helping to improve it!). Give genuine compliments, I guarantee the artist doesn't receive enough of them.

6. Get a feel for which artists are fairly open to critique and which aren't.
Critiquing is not "one size fits all"; some artists are touchier about their work than others.

7. Critique, don't criticize.
Critiquing is pointing out the flaws, and letting the artist make of it as they want. Most of the time they will either change the piece or chalk it up to style. In that case you drop it. Criticism is harping on a topic even after the artist has addressed it in some way. It is also presenting a critique in a way that is less than polite (in other words, not following the previous guidelines.

Note: These hints assume you aren't in charge of committing art into Wesnoth. In that case you can (of course) demand changes to a piece of art before it's accepted. It's still preferable to do so politely, though.

Section III: Taking other's critique
So we've submitted an artwork, how do we accept a critique?

1. Make it clear your intentions in posting the art.
Say whether you want to receive critiques, who you want to receive critiques from, and if you only want to receive certain types of critiques. "Can anyone proficient with the GIMP please tell me how to improve that flare effect?", "Can someone with experience in the area give me some hints on drawing noses, please?".
If you're submitting it for game use and don't want general comment, state so.

2. Post the art in context.
If it's a unit, show how it looks on terrain. If it's an attack icon, show it in the context of the attack screen. People (especially non-artists) will be able to offer more meaningful critiques if they can see how the art looks in context.

3. If you know something is wrong with the artwork, say so up front.
If you know the hand doesn't look right, say something like"I know the hand looks deformed; I just want comments on the face for now, please." This way you weed out the people telling you, the hand is wrong, and allow for more experienced artists to tell you why, as well as direct critique to what you want discussed.

4. Remember that, regardless of skill level or tact, the critiquer is trying to help your work to be the best possible. They aren't picking on you (usually).
If you feel people are being hostile to you, just let them know--if they weren't trying to be, they should change. If they don't, someone else can intervene.

Afterword

So here it is. If you have any questions about it or suggestions for improvement, let Irrevenant or me know, or follow advice stated at the beginning of the post.

By reading this, we hope you understand better how to post critique without potentially driving aspiring artists away. Now that it is here, we expect you to follow it.

Created by Irrevenant, with help from the community. Edited and posted here by Thrawn.

tsr linked me to the following article, which I at least really agree with, and would consider to be helpful reading for anyone perusing this topic. It's somewhat cautionary advice to artists about why they should be willing to recieve criticism - even if the criticism is invalid at times, they'll learn a great deal from cumulatively exposing themselves to it over the long run:https://web.archive.org/web/20150207015 ... ticism.php